Carbon-brush connection.



C. HAMBUECHEN.

CARBON BRUSH CONNECTION.

APPLICATION flLEVD- APR- ,17| 19l4.

Patented June 27,1916.

WMM awed:

UNITED STATES PATENT OFFICE.

CARL HAMBUECHENfOF BELLEVILLE, ILLINOIS, ASSIGNOR TO AMERICAN CARBON- &BATTERY CO., OF EAST S'l.v LOUIS, ILLINOIS, .A CORPORATION ILLINOIS.

CARBON-BRUSH CONNECTION.

Specification of Letters APatent. l Patented June 27, 1916.

Application filed April l?, 1914. Serial No. 832,663.

To all 'whom it may concern Be it known that I, CARL HAMBUECHEN, acitizen of :the United States, residing at Belleville, county of St.Clair, State of Illinois, have invented certain new and usefulImprovements in Carbon-Brush Connections; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,'such as will enable others skilled in the art to which it appertainstomake and use the same.

It is the object of the present invention to .provide a connectionbetween aflexible conductor and a carbon block such as is used for motorbrushes, dynamo brushes, and in theelectrical arts generally, andmore'particu* larly to provide a detachable connection whereby thecarbon block may be disconnected for renewal. E

To accomplish the foregoing object and others, which will hereinafterappear, the

carbonI block is provided with a cavity which is filled with an amalgam,such as a copper amalgam, the cavity being first preferably lined withcopper by electro-plating, and the' conductor is electrically connectedto this amalgam filling or plug by means of screws or the like threadedinto ,thev amalgam. Preferably a plate to which the flexible conductoris connected seats on the top of the brush and is held tight'by thesescrews.

In the accompanying drawings, Figure 1 is a side elevation of a motorbrush with the connection of the present invention; Fig. 2 is asectional elevation through thesame; Fig.

3 is a plan View; and Figs. 4 and 5 are sec- .tions through a modifiedform wherein the drilled holes filledwith amalgam do not converge.

Inthe embodiment illustrated,.the carbon block 1 may beof usual size andcomposition, and the flexible conductor` 2 is preferably of strandedcopper wire. At the top of the carbon block two converging holes 3 and 4are drilled until they intersect, forming a V- shaped`cavity in theupper part of the brush, say in the upper half. This cavity is thenlined with copper by electro-plating, since by this method an intimatecontact is established with the carbon surface of the cavity. The entirecavity is next filled with an amalgam, preferably a copper amalgam, toform a plug or illirgto which the other parts lmay be mechanicallyconnected. The composition of the amalgam and its mode or production mayvary, but satisfactory re.- sults are obtained by using parts by we1ghtof copper powder, or copper bronze powder, to 50 parts mercury. -Toprepare the amalgam, copper bronze powder is wet with water to a pasteand then the mercury 1s added, and the materials rubbed togetherthoroughly. A small quantity of dilute sulfuric acid is then added andthe mixture again rubbed. and complete amalgamation effected, afterwhich the material is washed free of acid. The amalgam is then in porousor puffy condition and can readily be tamped into the cavity without theuse of heavy pressure, and without danger of cracking or rupturing thecarbon block. It felts `together well, and after standing for 24 hoursbecomes hard and coherent and possessed of the desired mechanicalstrength. Other pro-` portions may be used, but with'toolow mercurycontent the mixture is too dry, and will notl pack or felt together'well, and with too much mercury it is too brittle to be tapped. Themixture above specified is of good conduetivity'and swells slightly onhardening and superficially amalgamates with the copper lining, and isotherwise well adapted for thepurpose, though I am aware that theamalgam may contain other components and be compounded in other ways.

The amalgam plug 'after hardening is drilled down the center of each legof the V and then is tamped to receive the threaded screws 5 and 6.These screws not only serve as current conductors to or from theamalgam, but also hold tightly clamped againstl the top of the brush a.conductive plate 7.

7 is also provided with an integral strip which is bent up and rolledtogether at its edges to form a socket 9 -into which the end of strandedconductor 2 may be received,

and by which it may betightly gripped without the need for soldering.Current passing through the stranded conductor 2 can fiow from plate 7into the carbon block, 4

and to facilitate-this the top face of the block and a portion of itssides may be electroplated with copper, but a large part ofthe currentflow passes through screws 5 and having and through the amalgamtrilling, tiret an even distribution of current is obtained wi iconsequent freedom from l local heen The entire connection ie tree freinsole' er other low fusing metals, or alloys, ano the amalgam fillingbecomes harder with age or i?" it l di gain adheres n'iost tenacimif-:lyin the cavil e l, and a satisfactory connection can be inaile lilitheither modification here disclosed, there is; no tlaiiger that 'the com.relator will be ii'ijured by the metal parte oi con-A nec-tion, for eventhough the brush iv down until the amalgam lilling coince ia Contactwith the coininutator,

l this; filling ie softer than the commutator and will not producedestructive Scratching.

am aware that various changes'. anal modifications in 'the forni and,arrangement oi parte may be niadejwithout depart-ing from the spirit oi'the invention as delinetl by the appended claims.

l claim r l. The con'ibination with a carbon brush a cavity, an amalgamfilling there in7 a etraiitled conductor, a plate coiinected t eaiflstral'nletl conductor anfl a Screw threaded inizi said amalgam andSecuring eaiil plate 'to Seid cabon brogli.

lhe combination oig a carbon having a plurality of holes, an elintro-plated lining 'iur said holes, an an'ialgani lilling for saidholes, a stranded conductor, a plate cared to said. stranded conductorand euren pans-ing threi'lgli. said plete ainl thro;

brush into said oinalgani lilling` 3. A carbiin oeh having a .ilnl'al fdrilled holes :t its top, a copper l filling for Said holes, ecrclgl'lio: said aan-lignei, a plate coverin i., ieexrei a etraniletlconductor connected with said e combination of a carbon brush, 'a c njlncting plate covering the top o'l: the carbon brush and securedthereto and hav-- :in uptnrnctl iz'itegral linger whereby the brush maybc lifted, and having an ripetending integral socket 'lor the receptionof a conductor and a. stranded flexible conductor ecatcil 1n Saulsocket; substantially 21S described. l

(l. The conibination of a carbon brush. lizrvlng a jblinfality ofconverging holes in the top thereof. forming a cavity, an electro-vpliitecl lining :for said cavity, an anialgani lilling l'or saiol cavitysupericially amalgainated :with said lining and coi'nprising copper:intl inercury in about equal parts, screws threaded into said amalgam,a conducting plate contacting with the top of the carbon brush, Saidplato being removable troni Said carbon brush upon withdrawal of thescreive, and a stranded iexible cmiductoi.l peri'nzo iicntly attached tosaid plate.

7. The combination of a carbon brush having a plurality of convergingcylindrical holes drilled in the top thereof, an :nnalgam lilling :lorsaid holes, screwe threaded into eaiil filling, a l'lat nulmeting platecolf'ering the top ol the carbon bi'nelrencl having an upturned integrallinger whereby the brush may be liited, and having an opstandingintegral socket 'for the reception of a conduce tor, said plate beingremovable from said.

gripped thereby; substantially described. ln ieetnnony whereot l alhx mysignature.

(l All L l lill? UE (ffl-.l E N.

